Thank you for your detailed explanation. I am able to run multiple design points together now. However, since I selected the execution mode as serial, I am unable to get an improvement in time required to solve the design points. Here is an image depicting the problem:

Even after selecting 10 design points sent to parameter set, and execution mode serial, only 3 design points were seen to be running at a time. I sent 10 desings in the parameter set as well.  The time taken for completing execution of the three points was found to be approximately 3 times the time for single point update which does not solve my problem.

In order to save time I want to run the multiple design points in parallel. What is limiting me here? Can it be related to number of cores or is there a problem in the simulation settings?

Thank you very much for your help.